Yes, the monthly FA draft drains the talent from the next years FA draft. In the RT leagues it also drains talent from the rookie draft, but that wouldn't happen with the TRAD leagues. Still overall it adds MUCH more than it subtracts.

The monthly FA drafts provide a good way for a team to rebuild. I don't think it slows down trading any for FA picks just looking at the trades in a few RT vs a few TRAD leagues. The FA picks have value because of the cut to 27 since you know you have a player vs in the rookie draft getting someone you may end up cutting to get to 27.

I think the monthly FA drafts are one of the best parts of the RT leagues. A big event each month. TRAD leagues might want fewer of them, but why none?